Nigeria has scotched rumours it is planning to pull out of the oil exporters' organisation, Opec.

The country's senior oil policy advisor, Rilwanu Lukman, who is also the current chairman of Opec, said Nigeria wished to remain an active member of the cartel.

The headline which set alarm bells ringing - "Nigeria Set to Leave Opec" - appeared 10 ten day ago in the British newspaper, Independent on Sunday.

Subsequent denials from Abuja suggested that the article was wrong.

But it did bring the issue out into the open - a welcome development for those who would like to see Nigeria pull out of Opec.

Opec restraints

That lobby certainly includes oil companies working in Nigeria, which have invested heavily but cannot produce to the full because of Opec restraints.

The oil market is hard to balance through export controls

Mr Lukman said Nigeria, whose quota has fallen by 20% since early in 2001, would argue for an increase "at the appropriate time".

"Of course we want our quota increased, just like every other member of Opec," he said.

Some pressure is also coming from outside Nigeria, particularly from the United States where there has been a lot of discussion recently about the need to make America less dependent on Middle East oil suppliers - particularly Saudi Arabia.

The debate has been led by a Jerusalem-based think-tank, the Institute for Advanced Strategic and Political Studies.

Their African Oil Policy Initiative Group has published a paper stressing the advantages of West African suppliers.

The group say the suppliers are closer, the transport routes are straightforward and much of the oil is offshore - and so less vulnerable to disruption.

Muslim pressure

It urges US companies to invest in the region, and urges the government to declare the Gulf of Guinea an 'Area of Vital Interest' to the United States.

But Nigeria's internal politics would make it hard to pull out of Opec.

Opec holds biannual summits of members' oil ministers

Muslim areas of the country would be very sensitive to any suggestion that the government was doing it to help the United States and make itself independent of the Arab and Islamic World.

It would also be embarrassing to leave Opec when Nigeria itself holds the chairmanship of the organisation.